Research On In-situ Cleaning Of Optical Surface By Electric Field And Airflow

Large laser driver is the core of laser inertial confinement fusion device. The improvement of load capacity and conversion efficiency is the bottleneck of this kind of device, and is also the key point of the research. And the damage threshold of optical elements is the key to improve the load capacity of the device. Surface imperfections of optical elements and pollution will lead to the damage of high energy laser through a time element surface, thereby reducing the damage threshold of the optical components, shortening the service life of the optical element, and increasing optical element maintenance cost. With the increase of the scale of the device, the online replaces and offline clean technology usually used lead to low efficiency of the device. Clean air knife and electrostatic technology are widely used in the field of dust removal. By combining the clean air knife and electrostatic technology, the mechanism and method of removing the pollutants o n the surface of the optical components are studied, which will lay the technical foundation for the design of the optical elements in the large laser driver.Firstly, through the analysis of sources and properties of the particles of pollutants generated in the operating process of large sized laser driver, the establishment of belts of the electrostatic, the adhesion force calculation mathematical model between particles with static electricity and optical element is established, the influence rule of pollutant particle size on the cohesive force and the electric field intensity needed for different sizes of particulate pollutant removing from the optical component surface are obtained.Secondly, the ANSYS software and the CST software are used respectively to build a simulation model of pollutant particle removal from optical element based on electric field, the influence law of supply voltage, electrode distance on the optical element surface electric field intensity distribution is analyzed, and electrical parameters needed for different sizes of particulate pollutant removing from the optical component surface are calculated. On this basis, combined with the wind knife fluid field calculation results, the design parameters of optical element surface contaminant particles removal based on the electric field and the flow is proposed.Finally, the optical element surface contaminant removal experiment device based on the electric field and the flow is designed and established. The influence law of electric field related parameters and flow parameters on pollutant removal is studied to verify the correctness of theoretical results.